1. Field of the Invention
The invention relates to the inner conductor of the resonator, the resonator comprises a casing, consisting of walls, lid and bottom of the casing resonator cavity in that the inner conductor is arranged to be located in said resonator, and into the resonator cavity, in a resonator cavity which has at least one inner conductor.
2. Description of the Prior Art
Cavity resonators are commonly used for making the filters in telecommunications networks, in particular, when the transmitted signal power is relatively high This is because these losses are due to the small size of resonator filters, which means only a small efficiency signal fade. In addition, the response characteristics are well controllable and adjustable to most stringent specifications,
Most of the filters and the filter pass band width of the space are intended to be fixed. In some of the filters the filter passband width is supposed to be constant, but on the pass-band is selected to be contained in a total area. This filter is required in addition to the basic tuning range for the passband transmission. This requires a lot of precise mechanical arrangements, and the adjustment to achieve the correct point.
The cavity resonator's coaxial resonator is shorter, this structure includes the inner conductor, consisting of side walls of the outer conductor, the bottom and the lid. Base and lid are in a galvanic connection with the outer conductor, and all three together forming a closed resonator cavity. In general, the lower end of the inner conductor galvanically linked to the bottom and the upper end of the air, when forming the transmission line resonator is short circuited at its lower end and open at its upper end. Resonant frequency of the resonator depends on the properties. If desired the filter which would be a number of resonance frequencies, it can be obtained by successive coupling of several resonators with different resonant frequencies. Such coordination, however, requires a lot of adjustment in order to achieve the desired frequency bands. Resonance transfer of such a filter is, however, very difficult, because it is taken into account also the links be the resonators.
German patent DE 3812782 shows a resonator, the inner conductor has a piston, which may be moving rapidly into the inner conductor to change the electrical characteristics of change of the resonance. Structure requires mechanics, so it becomes more expensive than conventional resonators of moving parts because it is more prone to defects.